Lockable wheels and subject support lifts including a lockable wheel

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 62/692,035, entitled “Lockable Wheels and Subject Support Lifts Including a Lockable Wheel” and filed on Jun. 29, 2018, the entirety of which is incorporated by reference herein.

BACKGROUND

Field

The present specification generally relates to subject support lifts including a lockable wheel and lockable wheels for use with subject support lifts.

Technical Background

Mobile lifts may be used in hospitals, other health care facilities, and home care settings to move a subject from one location to another or to assist in moving a subject from one location to another. Conventional mobile lifts utilize various accessories, such as a sling or other attachments to secure a subject to the mobile lift. An actuator of the mobile lift may lift the subject in a vertical direction so that the subject may be transported from one location to another. In one example, a caregiver may operate the mobile lift to raise the subject off a bed, reposition the subject by moving the mobile lift to a desired location, and then lower the subject at the destination.

When lifting a subject with a mobile lift, it is desirable to position the mobile lift directly over a center of mass of the subject. For example, when the center of mass of the subject is not positioned directly below the mobile lift, the subject may swing in a lateral and/or longitudinal direction when lifted, rather than moving only upward in the vertical direction. To address this issue, some conventional mobile lifts include pivoting wheels or casters that allow the mobile lift to move freely in the lateral and/or longitudinal direction. By moving in the lateral and/or longitudinal direction, the mobile lift may be repositioned over the center of mass of the subject as the subject is lifted. However, the pivoting wheels may make transporting the subject in the mobile lift difficult. For example, the pivoting wheels may provide minimal or no resistance to movement of the mobile lift in the lateral or longitudinal direction, making it difficult for a caregiver to push the mobile lift in a straight line, to navigate the mobile lift around an obstacle, or to otherwise move the mobile lift as desired.

Accordingly, a need exists for devices to assist in navigating subject support lift along a desired path.

SUMMARY

In one embodiment, a subject support lift includes a mast portion, a base portion, and a lockable wheel assembly coupled to the base portion, the lockable wheel assembly including an axle member, a lockable wheel coupled to the axle member and rotatable about an axle axis extending through the axle member, a pivot member pivotally coupled to the lockable wheel and defining an axis extending in a vertical direction that is transverse to the axle axis, where the lockable wheel is rotatable about the axis defined by the pivot member, a locking member coupled to one of the pivot member or the lockable wheel, the locking member being repositionable between a locked position, in which the locking member engages the other of the pivot member or the lockable wheel, and an unlocked position, in which the locking member is spaced apart from the other of the pivot member or the lockable wheel, a cable coupled to the locking member, and a handle coupled to the cable, where the handle selectively moves the locking member between the locked position and the unlocked position.

In another embodiment, a subject support lift including a mast portion extending upward in a vertical direction, and a base portion positioned at a bottom end of the mast portion, the base portion including a lockable leg extending between a front end and a rear end, a lockable wheel assembly coupled to the lockable leg, the lockable wheel assembly including a pivot member coupled to the lockable leg, a lockable wheel pivotally coupled to the lockable leg at the pivot member, and a locking member repositionable between a locked position and an unlocked position, where the lockable wheel is rotatable with respect to the lockable leg about an axis extending through the pivot member in the vertical direction with the locking member in the unlocked position, and the lockable wheel is fixed with respect to the lockable leg about the axis extending through the pivot member with the locking member in the locked position.

In yet another embodiment, a method for supporting a subject with a subject support lift includes moving the subject support lift toward the subject, the subject support lift including a mast portion and a base portion, the base portion including a lockable leg and a lockable wheel pivotally coupled to the lockable leg, moving the lockable leg outward from a subject support lift centerline, connecting the subject to the subject support lift, lifting the subject with the subject support lift in a vertical direction, locking the lockable wheel such that the lockable wheel is fixed with respect to the lockable leg about an axis extending in the vertical direction, and moving the subject connected to the subject support lift in a direction transverse to the vertical direction.

Additional features of person lifting devices including lockable wheels described herein will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows, the claims, as well as the appended drawings.

It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated into and constitute a part of this specification. The drawings illustrate the various embodiments described herein, and together with the description serve to explain the principles and operations of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

<figref idref="DRAWINGS">FIG. 1</figref> schematically depicts a front perspective view of a subject support lift according to one or more embodiments shown and described herein;

<figref idref="DRAWINGS">FIG. 2</figref> schematically depicts a top view of the subject support lift of <figref idref="DRAWINGS">FIG. 1</figref>, according to one or more embodiments shown and described herein;

<figref idref="DRAWINGS">FIG. 3A</figref> schematically depicts a cross-section of a lockable wheel assembly of the subject support lift along section <b>3</b>A-<b>3</b>A of <figref idref="DRAWINGS">FIG. 2</figref>, according to one or more embodiments shown and described herein;

<figref idref="DRAWINGS">FIG. 3B</figref> schematically depicts a cross-section of the lockable wheel assembly of <figref idref="DRAWINGS">FIG. 3A</figref> along section <b>3</b>B-<b>3</b>B of <figref idref="DRAWINGS">FIG. 3A</figref>, according to one or more embodiments shown and described herein;

<figref idref="DRAWINGS">FIG. 4</figref> schematically depicts a cross-section of another lockable wheel assembly of the subject support lift along section <b>4</b>-<b>4</b> of <figref idref="DRAWINGS">FIG. 2</figref>, according to one or more embodiments shown and described herein;

<figref idref="DRAWINGS">FIG. 5A</figref> schematically depicts a side view of another lockable wheel assembly of the subject support lift of <figref idref="DRAWINGS">FIG. 2</figref>, according to one or more embodiments shown and described herein;

<figref idref="DRAWINGS">FIG. 5B</figref> schematically depicts a rear perspective view of the lockable wheel assembly of <figref idref="DRAWINGS">FIG. 5A</figref>, according to one or more embodiments shown and described herein;

<figref idref="DRAWINGS">FIG. 6</figref> schematically depicts a top view of another lockable wheel assembly of the subject support lift along section <b>6</b>-<b>6</b> of <figref idref="DRAWINGS">FIG. 1</figref>, according to one or more embodiments shown and described herein;

<figref idref="DRAWINGS">FIG. 7A</figref> schematically depicts a top view of the lockable wheel assembly of <figref idref="DRAWINGS">FIG. 6</figref> rotating about an axis, according to one or more embodiments shown and described herein;

<figref idref="DRAWINGS">FIG. 7B</figref> schematically depicts a top view of the lockable wheel assembly of <figref idref="DRAWINGS">FIG. 6</figref> continuing to rotate about the axis, according to one or more embodiments shown and described herein; and

<figref idref="DRAWINGS">FIG. 7C</figref> schematically depicts a top view of the lockable wheel assembly of <figref idref="DRAWINGS">FIG. 6</figref> moving oriented in a lateral direction, according to one or more embodiments shown and described herein.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of lockable wheel assemblies and subject support lifts including lockable wheel assemblies, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. In embodiments, a subject support lift includes a mast portion extending upward in a vertical direction and a base portion positioned at a bottom end of the mast portion. The base portion includes a lockable leg extending between a front end and a rear end and a lockable wheel assembly including a pivot member coupled to the leg. The lockable wheel assembly includes a locking member and a lockable wheel pivotally coupled to the lockable leg at the pivot member, where locking member is repositionable between an unlocked position, in which the lockable wheel is rotatable with respect to the lockable leg about an axis extending through the pivot member in the vertical direction, and a locked position, in which the lockable wheel is fixed with respect to the lockable leg at the pivot member. Because locking member is selectively repositionable between a locked position and an unlocked position, the lockable wheel may be rotatable when lifting a subject, so that the subject support lift may freely move to position the subject support lift over the center of mass of the subject. The wheel may also be fixed with respect to the leg of the subject support lift in the locked position to resist movement of the lift in a lateral direction when moving the subject from one location to another. This and other embodiments of lockable wheels and subject support lifts including lockable wheels are described below with reference to the appended drawings.

As used herein, the term “longitudinal direction” refers to the forward-rearward direction of the components of the subject support lift (i.e., in the +/−Y-direction as depicted). The term “lateral direction” refers to the cross-wise direction of the components of the subject support lift (i.e., in the +/−X-direction as depicted), and is transverse to the longitudinal direction. The term “vertical direction” refers to the upward-downward direction of the components of the subject support lift (i.e., in the +/−Z-direction as depicted).

Referring initially to <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, a front perspective view and a top view of a subject support lift <b>100</b> are schematically depicted, respectively. The subject support lift <b>100</b> generally includes a mast portion <b>102</b> extending upward in the vertical direction from a base portion <b>101</b>. The mast portion <b>102</b> may include a vertical member <b>104</b> that generally extends upward in the vertical direction, and a horizontal member <b>106</b> that is pivotally coupled to and extends forward from the vertical member <b>104</b> in the longitudinal direction. The subject support lift <b>100</b> further includes a sling bar <b>108</b> that is selectively coupled to the horizontal member <b>106</b>. The sling bar <b>108</b> may be utilized to selectively couple a subject support device (e.g., a sling, a vest, or the like) to the subject support lift <b>100</b>.

In embodiments, the subject support lift <b>100</b> includes a motor <b>103</b> coupled to the mast portion <b>102</b> that moves the horizontal member <b>106</b> with respect to the vertical member <b>104</b>. In particular, in the embodiment depicted in <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, the motor <b>103</b> is positioned on the vertical member <b>104</b> and engaged with the horizontal member <b>106</b>. As noted above, the horizontal member <b>106</b> may be pivotally coupled to the vertical member <b>104</b>, and the motor <b>103</b> may move the horizontal member <b>106</b> about the pivot, thereby moving the horizontal member <b>106</b> in the vertical direction. By moving horizontal member <b>106</b> in the vertical direction, the motor <b>103</b> moves the sling bar <b>108</b> selectively coupled to the horizontal member <b>106</b> in the vertical direction. The motor <b>103</b> may include any suitable actuation device to move the horizontal member <b>106</b> with respect to the vertical member <b>104</b>, such as a direct current (DC) electric motor, an alternating current (AC) motor, a pneumatically driven motor, a hydraulically driven motor, or the like. While the embodiment depicted in <figref idref="DRAWINGS">FIGS. 1 and 2</figref> includes the motor <b>103</b> coupled to the vertical member <b>104</b> and engaged with the horizontal member <b>106</b>, the motor <b>103</b> may be positioned at any suitable location of the subject support lift <b>100</b> to move the horizontal member <b>106</b> with respect to the vertical member <b>104</b>. For example, the motor <b>103</b> may be coupled to the horizontal member <b>106</b> or the base portion <b>101</b> to move the horizontal member <b>106</b>, and accordingly the sling bar <b>108</b>, in the vertical direction. Furthermore, while the embodiment depicted in <figref idref="DRAWINGS">FIGS. 1 and 2</figref> depicts a mast portion <b>102</b> including a vertical member <b>104</b> pivotally coupled to a horizontal member <b>106</b>, it should be understood that the mast portion <b>102</b> may include any suitable construction to facilitate the selective movement of the sling bar <b>108</b> in the vertical direction. For example, in some embodiments, the vertical member <b>104</b> may include a telescoping design such that the vertical member <b>104</b> may be selectively extended and retracted in the vertical direction, and the motor <b>103</b> may move the vertical member <b>104</b> up and down in the vertical direction to move the sling bar <b>108</b> in the vertical direction.

The base portion <b>101</b> of the subject support lift <b>100</b> is positioned at a bottom end of the mast portion <b>102</b> and generally includes a base member <b>110</b> extending in the lateral direction, and a lockable leg <b>120</b> and a pivotable leg <b>160</b> that are each pivotally coupled to the base member <b>110</b>. The base member <b>110</b> generally extends across a subject support lift centerline <b>10</b> that bisects the subject support lift <b>100</b> in the longitudinal direction.

In the embodiment depicted in <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, the lockable leg <b>120</b> and the pivotable leg <b>160</b> are pivotally coupled to the base member <b>110</b> at respective pivot couplings <b>112</b>. The lockable leg <b>120</b> extends between a rear end <b>124</b> and a front end <b>122</b> that is positioned opposite the rear end <b>124</b> in the longitudinal direction. Similarly, the pivotable leg <b>160</b> extends between a rear end <b>164</b> and a front end <b>162</b> that is positioned opposite the rear end <b>164</b> in the longitudinal direction. In embodiments, the lockable leg <b>120</b> and the pivotable leg <b>160</b> are repositionable between an extended position and a retracted position. In particular, the lockable leg <b>120</b> is pivotable about a pivot coupling axis <b>114</b> of the pivot coupling <b>112</b> that couples the lockable leg <b>120</b> to the base member <b>110</b>. The lockable leg <b>120</b> is repositionable between an extended position and a retracted position, where the front end <b>122</b> of the lockable leg <b>120</b> is positioned closer to the subject support lift centerline <b>10</b> in the retracted position. Similarly, the pivotable leg <b>160</b> is pivotable about a pivot coupling axis <b>114</b> of the pivot coupling <b>112</b> that couples the pivotable leg <b>160</b> to the base member <b>110</b>. The pivotable leg <b>160</b> is repositionable between an extended position and a retracted position, wherein the front end <b>162</b> is poisoned closer to the subject support lift centerline <b>10</b> in the retracted position. In embodiments, the lockable leg <b>120</b> and the pivotable leg <b>160</b> may be coupled to a motor <b>105</b> that selectively repositions the lockable leg <b>120</b> and the pivotable leg <b>160</b> between the extended position and the retracted position. In some embodiments, the motor <b>105</b> may simultaneously move both the lockable leg <b>120</b> and the pivotable leg <b>160</b> between the extended and the retracted positions. In other embodiments, the motor <b>105</b> may selectively move one or the other of the lockable leg <b>120</b> and the pivotable leg <b>160</b> between the extended and the retracted positions. By repositioning the lockable leg <b>120</b> and/or the pivotable leg <b>160</b> between an extended position and a retracted position, a distance d between the front end <b>122</b> of the lockable leg <b>120</b> and the front end <b>162</b> of the pivotable leg <b>160</b> may be increased or decreased. By increasing the distance d between the front ends <b>122</b>, <b>162</b> of the pivotable leg <b>160</b> and the lockable leg <b>120</b>, the pivotable leg <b>160</b> and the lockable leg <b>120</b> may straddle an object supporting a subject such that the sling bar <b>108</b> may be positioned over the subject. For example, a subject may be sitting on an object, such as chair, a toilet, or the like, and the pivotable leg <b>160</b> and the lockable leg <b>120</b> may be positioned on opposite sides to straddle the object such that the sling bar <b>108</b> may be positioned over the subject.

The pivotable leg <b>160</b> generally includes a pair of pivotable wheels <b>170</b> that are pivotally coupled to the front end <b>162</b> and the rear end <b>164</b> of the pivotable leg <b>160</b>. The pivotable wheels <b>170</b> are generally rotatable about pivotable wheel axes <b>172</b> that extend in the vertical direction. The lockable leg <b>120</b> generally includes a pivotable wheel <b>170</b> pivotally coupled to the rear end <b>124</b> of the lockable leg <b>120</b>, and a lockable wheel assembly <b>130</b> coupled to the front end <b>122</b> of the lockable leg <b>120</b>. The pivotable wheel <b>170</b> pivotally coupled to the rear end <b>124</b> of the lockable leg <b>120</b> is generally rotatable about the pivotable wheel axis <b>172</b> extending in the vertical direction and the lockable wheel assembly <b>130</b> is also generally rotatable about an axis <b>132</b> that extends in the vertical direction. The lockable wheel assembly <b>130</b> is selectively repositionable between a locked position, in which the lockable wheel assembly <b>130</b> is fixed with respect to the lockable leg <b>120</b> about the axis <b>132</b>, and an unlocked position, in which at least a portion of the lockable wheel assembly <b>130</b> is rotatable about the axis <b>132</b>, as described in greater detail herein. While the embodiment depicted in <figref idref="DRAWINGS">FIGS. 1 and 2</figref> includes the lockable wheel assembly <b>130</b> coupled to the front end <b>122</b> of the lockable leg <b>120</b>, in other embodiments, the lockable wheel assembly <b>130</b> may be coupled to the rear end <b>124</b> of the lockable leg <b>120</b>, and the lockable leg <b>120</b> may include a pivotable wheel <b>170</b> coupled to the front end <b>122</b> of the lockable leg <b>120</b>.

Referring to <figref idref="DRAWINGS">FIG. 3A</figref>, a cross-section view of the lockable wheel assembly <b>130</b> along section <b>3</b>A-<b>3</b>A of <figref idref="DRAWINGS">FIG. 2</figref> is depicted. The lockable wheel assembly <b>130</b> is coupled to the lockable leg <b>120</b>, and generally includes a pivot member <b>140</b> coupled to the lockable leg <b>120</b> and a lockable wheel <b>134</b> coupled to the pivot member <b>140</b>. In the embodiment depicted in <figref idref="DRAWINGS">FIG. 3A</figref>, the pivot member <b>140</b> includes a connection portion <b>146</b> that is coupled to the lockable leg <b>120</b> and that defines a cavity <b>148</b> extending upward into the connection portion <b>146</b>. The lockable wheel <b>134</b> is pivotally coupled to the lockable leg <b>120</b> through the connection portion <b>146</b>, and the pivot member <b>140</b> may include one or more bearings positioned between the connection portion <b>146</b> and the lockable wheel <b>134</b> such that the lockable wheel <b>134</b> is selectively rotatable about the axis <b>132</b>. The bearings may include any suitable bearings to permit rotation of the lockable wheel <b>134</b> with respect to the lockable leg <b>120</b>, such as ball bearings, roller bearings, magnetic bearings, or the like.

Referring collectively to <figref idref="DRAWINGS">FIGS. 3A and 3B</figref>, the cross-section of the lockable wheel assembly <b>130</b> along section <b>3</b>A-<b>3</b>A of <figref idref="DRAWINGS">FIG. 2</figref> and a cross-section of the lockable wheel assembly <b>130</b> along section <b>3</b>B-<b>3</b>B of <figref idref="DRAWINGS">FIG. 3A</figref> are depicted, respectively. The lockable wheel <b>134</b> is coupled to the connection portion <b>146</b> through an axle member <b>136</b> and the lockable wheel <b>134</b> is rotatable with respect to the axle member <b>136</b>. In particular, the lockable wheel <b>134</b> is rotatable about an axle axis <b>131</b> that extends through the axle member <b>136</b> in the lateral direction as depicted, such that the lockable wheel <b>134</b> may rotate along a surface, such as a floor.

In embodiments, the lockable wheel assembly <b>130</b> includes a locking member <b>142</b> that is positioned at least partially within an axle cavity <b>137</b> defined by the axle member <b>136</b>, such that the locking member <b>142</b> is rotatable about the axis <b>132</b> with the axle member <b>136</b> and the lockable wheel <b>134</b>. The locking member <b>142</b> may be bounded by the axle cavity <b>137</b> in the longitudinal and the lateral directions as depicted, such that movement of the locking member <b>142</b> in the lateral and longitudinal direction is restricted by the axle cavity <b>137</b>. In embodiments, the locking member <b>142</b> is coupled to a cable <b>182</b> that extends through the connection portion <b>146</b> and that is movable in the vertical direction, to move the locking member <b>142</b> in the vertical direction. The cable <b>182</b> may generally include any suitable structure to facilitate moving the locking member <b>142</b> in the vertical direction, and may include a metal wire, a nylon rope, a composite, or the like.

In some embodiments, the locking member <b>142</b> is engaged with a biasing member <b>144</b> that biases the locking member <b>142</b> in the vertical direction. The biasing member <b>144</b> may include any suitable construction to bias the locking member <b>142</b> in the vertical direction, and may include a tension spring, a torsion spring, or a compression spring. In some embodiments, the biasing member <b>144</b> biases the locking member <b>142</b> downward in the vertical direction. In other embodiments, the biasing member biases the locking member upward in the vertical direction.

The locking member <b>142</b> is repositionable between an unlocked position, as depicted in <figref idref="DRAWINGS">FIG. 3A</figref> and in which the locking member <b>142</b> is spaced apart from the cavity <b>148</b> of the connection portion <b>146</b>, and a locked position, in which the locking member <b>142</b> is positioned at least partially within the cavity <b>148</b> of the connection portion <b>146</b>. When at least a portion of the locking member <b>142</b> is positioned within the cavity <b>148</b> of the connection portion <b>146</b>, movement of the locking member <b>142</b> with respect to the connection portion <b>146</b> may be restricted. In particular, the cavity <b>148</b> may bound the locking member <b>142</b> in the longitudinal direction and the lateral direction, thereby restricting movement of the locking member <b>142</b> with respect to the connection portion <b>146</b>. As noted above, the locking member <b>142</b> is bounded by the axle cavity <b>137</b> in the longitudinal and the lateral directions. Accordingly, when the locking member <b>142</b> is positioned at least partially within the cavity <b>148</b>, the locking member <b>142</b> is engaged with and bounded in the longitudinal and the lateral directions by both the connection portion <b>146</b> and the axle member <b>136</b>. Because the locking member <b>142</b> is bounded by the cavity <b>148</b> of the connection member <b>146</b> and the axle cavity <b>137</b> of the axle member <b>136</b> in the longitudinal and the lateral directions, the axle member <b>136</b> is fixed with respect to the connection member <b>146</b> about the axis <b>132</b> when the locking member <b>142</b> is positioned at least partially within the cavity <b>148</b> of the connection member <b>146</b>. By fixing the axle member <b>136</b> with respect to the connection member <b>146</b> about the axis <b>132</b>, the lockable wheel <b>134</b> may be fixed with respect to the lockable leg <b>120</b> about the axis <b>132</b> through the axle member <b>136</b>, the locking member <b>142</b>, and the connection portion <b>146</b>. In the embodiment depicted in <figref idref="DRAWINGS">FIGS. 3A and 3B</figref>, the locking member <b>142</b> is positionable within the cavity <b>148</b> of the connection portion <b>146</b> when the lockable wheel <b>134</b> is aligned with the lockable leg <b>120</b>, e.g., when the axle axis <b>131</b> extends in a direction orthogonal to the lockable leg <b>120</b>.

Referring collectively to <figref idref="DRAWINGS">FIGS. 1 and 3A</figref>, in some embodiments, the cable <b>182</b> is coupled to a handle <b>180</b>. In the embodiment depicted in <figref idref="DRAWINGS">FIGS. 1 and 3A</figref>, the handle <b>180</b> is coupled to the mast portion <b>102</b> and is coupled to the locking member <b>142</b> through the cable <b>182</b>. The handle <b>180</b> is repositionable between an engaged position, in which the handle <b>180</b> moves the locking member <b>142</b> into the locked position, and a disengaged position, in which the handle <b>180</b> moves the locking member <b>142</b> into the unlocked position. As described above, the biasing member <b>144</b> may bias the locking member <b>142</b> in the vertical direction. In some embodiments, the biasing member <b>144</b> biases the locking member <b>142</b> into the cavity <b>148</b> (i.e., into the locked position), and the locking member <b>142</b> is moved into the unlocked position through movement cable <b>182</b> in the vertical direction via moving the handle into the disengaged position. In other embodiments, the biasing member <b>144</b> may bias the locking member out of the cavity <b>148</b> (i.e., into the unlocked position), and the locking member <b>142</b> is moved into the locked position through movement of the cable <b>182</b> in the vertical direction via moving the handle <b>180</b> into the engaged position.

Referring again to <figref idref="DRAWINGS">FIG. 1</figref>, by fixing the lockable wheel <b>134</b> with respect to the lockable leg <b>120</b> about the axis <b>132</b>, the lateral movement of the subject support lift <b>100</b> may be restricted. More particularly, because the lockable wheel <b>134</b> is fixed with respect to the lockable leg <b>120</b> about the axis <b>132</b> with the locking member <b>142</b> (<figref idref="DRAWINGS">FIG. 3A</figref>) in the locked position, the lockable wheel <b>134</b> may be rotatable about the axle axis <b>131</b> (<figref idref="DRAWINGS">FIG. 3A</figref>), but may resist movement in the lateral direction as depicted. By resisting movement in the lateral direction, the lockable wheel <b>134</b> may reduce the force required to navigate the subject support lift <b>100</b> along a straight line in the longitudinal direction, reducing the burden placed on a caregiver to move the subject support lift <b>100</b> as desired when transporting a subject with the subject support lift <b>100</b>. Furthermore, by resisting movement in the lateral direction, the lockable wheel <b>134</b> may provide a pivot point about which the rest of the subject support lift <b>100</b> may be rotated, which may assist a caregiver in navigating the subject support lift <b>100</b> as desired when transporting a subject with the subject support lift <b>100</b>.

However, when lifting a subject with the subject support lift <b>100</b>, it may be desirable for the lockable wheel <b>134</b> to be rotatable with respect to the lockable leg about the axis <b>132</b>. In particular, as noted above, the subject support lift <b>100</b> includes the pivotable wheels <b>170</b> at the front end <b>162</b> and the rear end <b>164</b> of the pivotable leg <b>160</b>, as well as at the rear end <b>124</b> of the lockable leg <b>120</b>, each of which are rotatable about pivotable wheel axes <b>172</b> that extend in the vertical direction. Because the subject support lift <b>100</b> includes pivotable wheels <b>170</b> and the lockable wheel assembly <b>130</b> that are each rotatable about axes <b>172</b>, <b>132</b> extending in the vertical direction, the subject support lift <b>100</b> may move freely in the lateral and the longitudinal directions through the rotation of the pivotable wheels <b>170</b> and the lockable wheel assembly <b>130</b>. Free movement of the subject support lift <b>100</b> may be desirable when lifting a subject with the mast portion <b>102</b>, such that the subject support lift <b>100</b> may be moved to align the sling bar <b>108</b> over a center of mass of the subject.

For example and referring to <figref idref="DRAWINGS">FIG. 2</figref>, the sling bar <b>108</b> defines a sling bar center of mass <b>109</b>, and a subject to be moved with the subject support lift <b>100</b> may define a subject center of mass <b>12</b>. When lifting the subject in the vertical direction through a sling, a vest, or the like coupled to the sling bar <b>108</b>, it is desirable for the sling bar center of mass <b>109</b> to be positioned over the subject center of mass <b>12</b>. In particular, once a subject is lifted off of a support surface (e.g., a bed, a chair, or the like), the subject center of mass <b>12</b> will move toward the sling bar center of mass <b>109</b> under the force of gravity. In other words, the subject will “swing” toward the sling bar center of mass <b>109</b>, and may continue swinging until the subject center of mass <b>12</b> comes to rest underneath the sling bar center of mass <b>109</b>. To reduce “swinging” the subject, it is desirable to align the sling bar center of mass <b>109</b> with the subject center of mass <b>12</b> before the subject is lifted off of the support surface.

With the subject support lift <b>100</b> freely movable in the longitudinal and the lateral direction, as the sling bar <b>108</b> moves upward in the vertical direction, the subject support lift <b>100</b> may be “pulled” toward the subject center of mass <b>12</b> until the sling bar center of mass <b>109</b> is positioned over the subject center of mass <b>109</b>. Without being bound by theory, as the sling bar <b>108</b> moves upward in the vertical direction, the sling bar <b>108</b> (through a sling, a vest, or the like coupled to the sling bar <b>108</b> and attached to the subject) applies a force to the subject, which is resisted by an equal and opposite force applied to the sling bar <b>108</b> by the subject. The force applied to the sling bar <b>108</b> by the subject acts to pull the subject support lift <b>100</b> toward the subject center of mass <b>12</b>. With the subject support lift <b>100</b> freely movable in the longitudinal direction, the subject support lift <b>100</b> moves toward the subject center of mass <b>12</b> under the force applied to the sling bar <b>108</b> by the subject (i.e., in a forward direction <b>14</b> and in a sideways lateral direction <b>16</b> as depicted), until the sling bar center of mass <b>109</b> is positioned over the subject center of mass <b>12</b>. As the sling bar <b>108</b> continues to move upward, the subject may then be lifted off of a support surface (e.g., a bed, a chair, or the like) with the sling bar center of mass <b>109</b> positioned over the subject center of mass <b>12</b>. In this way, a subject's “swinging” when being lifted by the subject support lift <b>100</b> may be minimized by utilizing a subject support lift <b>100</b> including pivotable wheels <b>170</b> and a lockable wheel assembly <b>130</b> that are each rotatable about axes <b>172</b>, <b>132</b> extending in the vertical direction allowing the subject support lift <b>100</b> to move freely in the lateral and the longitudinal directions.

Accordingly, by including a selectively lockable wheel <b>134</b>, the subject support lift <b>100</b> may be freely movable in the lateral and the longitudinal directions when lifting a subject so as to reduce swinging the subject as described above, and lateral movement of the subject support lift <b>100</b> may be restricted when moving a subject in the longitudinal direction with the subject support lift <b>100</b>.

Referring to <figref idref="DRAWINGS">FIG. 4</figref>, a cross-section of another lockable wheel assembly <b>130</b> is depicted along section <b>4</b>-<b>4</b> of <figref idref="DRAWINGS">FIG. 2</figref>. The embodiment depicted in <figref idref="DRAWINGS">FIG. 4</figref> includes the connection portion <b>146</b> including the cavity <b>148</b>, the lockable wheel <b>134</b>, and the axle member <b>136</b> including the axle cavity <b>137</b>, similar to the embodiment described above with respect to <figref idref="DRAWINGS">FIGS. 3A and 3B</figref>. However, in the embodiment depicted in <figref idref="DRAWINGS">FIG. 4</figref>, the lockable wheel assembly <b>130</b> includes a solenoid <b>184</b> that moves the locking member <b>142</b> between the locked position and the unlocked position. Particularly, the solenoid <b>184</b> may be selectively charged with current to draw the locking member <b>142</b> upward in the vertical direction. In the embodiment depicted in <figref idref="DRAWINGS">FIG. 4</figref>, the cable <b>182</b> electrically couples the solenoid <b>184</b> to the handle <b>180</b> (<figref idref="DRAWINGS">FIG. 1</figref>). In this embodiment, the cable <b>182</b> may generally include a construction suitable for conducting electrical current, such as copper wiring or the like.

The lockable wheel assembly <b>130</b> further includes the biasing member <b>144</b> that biases the locking member <b>142</b> in the vertical direction. In the embodiment depicted in <figref idref="DRAWINGS">FIG. 4</figref>, the biasing member <b>144</b> may bias the locking member <b>142</b> downward in the vertical direction (i.e., into the unlocked position), and the solenoid <b>184</b> may move the locking member <b>142</b> into the locked position when charged with current. In other embodiments, the biasing member <b>144</b> may bias the locking member <b>142</b> upward into the cavity <b>148</b> (i.e., into the locked position), and the solenoid <b>184</b> may move the locking member <b>142</b> into the unlocked position when charged with current.

Referring to <figref idref="DRAWINGS">FIGS. 5A and 5B</figref>, a side view and a lower perspective view of another lockable wheel assembly <b>130</b> is schematically depicted. The lockable wheel assembly <b>130</b> includes the lockable wheel <b>134</b> and the pivot member <b>140</b> coupled to the lockable leg <b>120</b>. In the embodiment depicted in <figref idref="DRAWINGS">FIGS. 5A and 5B</figref>, the lockable wheel assembly <b>130</b> further includes a disc <b>150</b> that extends at least partially around the axis <b>132</b> of the lockable wheel assembly <b>130</b>. In embodiments, the disc <b>150</b> is coupled to the lockable wheel <b>134</b>, such that the disc <b>150</b> rotates about the axis <b>132</b> of the pivot member <b>140</b> with the lockable wheel <b>134</b>.

The lockable wheel assembly <b>130</b> further includes the locking member <b>142</b> that is selectively engageable with the disc <b>150</b>. In particular, in the embodiment depicted in <figref idref="DRAWINGS">FIGS. 5A and 5B</figref>, the locking member <b>142</b> is coupled to the lockable leg <b>120</b> and is extendable in the longitudinal direction to selectively engage the disc <b>150</b>. When extended, the locking member <b>142</b> engages the disc <b>150</b>, such that the disc <b>150</b>, and accordingly the lockable wheel <b>134</b>, are fixed with respect to the lockable leg <b>120</b> about the axis <b>132</b>. When retracted, the locking member <b>142</b> is spaced apart from the disc <b>150</b>, such that the disc <b>150</b>, and accordingly the lockable wheel <b>134</b>, are rotatable with respect to the lockable leg <b>120</b> about the axis <b>132</b>. In embodiments, the locking member <b>142</b> may be coupled to the handle <b>180</b> (<figref idref="DRAWINGS">FIG. 1</figref>) through a cable <b>182</b> (<figref idref="DRAWINGS">FIG. 3A</figref>) and the locking member <b>142</b> may be extended and retracted (i.e., moved between the locked position and the unlocked position) via movement of the handle <b>180</b> (<figref idref="DRAWINGS">FIG. 1</figref>) between the engaged position and the disengaged position.

Referring now to <figref idref="DRAWINGS">FIG. 6</figref>, a cross section of another lockable wheel assembly <b>130</b> along section <b>6</b>-<b>6</b> of <figref idref="DRAWINGS">FIG. 1</figref> is schematically depicted. In the embodiment depicted in <figref idref="DRAWINGS">FIG. 6</figref>, the pivot member <b>140</b> defines the cavity <b>148</b>, and locking member <b>142</b> of the lockable wheel assembly <b>130</b> includes a turnable axle <b>281</b> positioned within the cavity <b>148</b>. The turnable axle <b>281</b> is coupled to the lockable wheel <b>134</b> and generally includes an elliptical shape having a turnable axle major axis <b>280</b> and turnable axle minor axis <b>282</b>. The cavity <b>148</b> similarly includes an elliptical shape having a cavity major axis <b>248</b> and a cavity minor axis <b>250</b>. In embodiments, a length of the turnable axle major axis <b>280</b> is less than a length of the cavity minor axis <b>250</b>, such that the turnable axle <b>281</b> is rotatable within the cavity <b>148</b>. Furthermore, the turnable axle <b>281</b> is coupled to the lockable wheel <b>134</b> such that the turnable axle <b>281</b> rotates with the lockable wheel <b>134</b> with respect to the cavity <b>148</b> about the axis <b>132</b>.

The turnable axle <b>281</b> may move within the cavity <b>148</b> in the longitudinal and/or the lateral directions. When the subject support lift <b>100</b> (<figref idref="DRAWINGS">FIG. 1</figref>) is moving forward in the longitudinal direction (i.e., in the +y-direction as depicted), the turnable axle <b>281</b> may be positioned in a front end of the cavity <b>148</b> such that the turnable axle major axis <b>280</b> and the cavity major axis <b>248</b> are aligned and the turnable axle minor axis <b>282</b> is positioned forward of the cavity minor axis <b>250</b> in the longitudinal direction. With the turnable axle major axis <b>280</b> and the cavity major axis <b>248</b> aligned and with the turnable axle <b>281</b> positioned in the front end of the cavity <b>148</b>, rotation of the lockable wheel <b>134</b> about the axis <b>132</b> may be restricted. More particularly, with the turnable axle <b>281</b> positioned within the front portion of the cavity <b>148</b>, the turnable axle <b>281</b> may be bounded by the elliptical shape of the cavity <b>148</b>, restricting rotation of the turnable axle <b>281</b>, and accordingly the lockable wheel <b>134</b>, about the axis <b>132</b>. In this manner, the turnable axle <b>281</b> may be positioned in the locked position when the subject support lift <b>100</b> (<figref idref="DRAWINGS">FIG. 1</figref>) is moving forward in the longitudinal direction.

Referring collectively to <figref idref="DRAWINGS">FIGS. 7A-7C</figref>, the turnable axle <b>281</b> is depicted progressively rotating about the axis <b>132</b> until the lockable wheel <b>134</b> is oriented in the lateral direction. More particularly, as depicted in <figref idref="DRAWINGS">FIG. 7A</figref>, the turnable axle <b>281</b> may be moved rearward within the cavity <b>148</b> in the longitudinal direction (i.e., in the −y-direction as depicted). In embodiments, the turnable axle <b>281</b> may be moved rearward within the cavity <b>148</b> when the subject support lift <b>100</b> (<figref idref="DRAWINGS">FIG. 1</figref>) ceases moving forward in the longitudinal direction (i.e., in the +y-direction as depicted), and/or by moving the subject support lift <b>100</b> (<figref idref="DRAWINGS">FIG. 1</figref>) rearward in the longitudinal direction (i.e., in the −y-direction as depicted). As the turnable axle <b>281</b> moves rearward within the cavity <b>148</b>, the turnable axle <b>281</b> may no longer be bounded by the elliptical shape of the cavity <b>148</b>, allowing rotation of the turnable axle <b>281</b>, and accordingly the lockable wheel <b>134</b>, about the axis <b>132</b>. As noted above, the length of the turnable axle major axis <b>280</b> may be less than the length of the cavity minor axis <b>250</b>, such that the turnable axle <b>281</b> may be fully rotatable about the axis <b>132</b> when the turnable axle <b>281</b> is positioned at the center of the cavity <b>148</b>. In this way, the turnable axle <b>281</b> may be repositioned between the locked position and the unlocked position by moving the turnable axle <b>281</b> forward and rearward in the longitudinal direction within the cavity <b>148</b>. Because the turnable axle <b>281</b> is positioned in the locked position when the subject support lift <b>100</b> (<figref idref="DRAWINGS">FIG. 1</figref>) is being moved forward in the longitudinal direction, similar to the embodiments described above, the lockable wheel assembly <b>130</b> may assist in resisting lateral movement of the subject support lift <b>100</b> (<figref idref="DRAWINGS">FIG. 1</figref>) when the subject support lift <b>100</b> is being moved forward in the longitudinal direction.

Accordingly, it should now be understood that embodiments according to the present disclosure include subject support lifts including lockable wheel assemblies. The lockable wheel assemblies generally include a locking member and a lockable wheel pivotally coupled to a lockable leg of the subject support at the pivot member, where locking member is repositionable between an unlocked position, in which the lockable wheel is rotatable with respect to the lockable leg about an axis extending through the pivot member in the vertical direction, and a locked position, in which the lockable wheel is fixed with respect to the lockable leg at the pivot member. Because locking member is selectively repositionable between a locked position and an unlocked position, the lockable wheel may be rotatable when lifting a subject, so that the subject support lift may freely move to position the subject support lift over the center of mass of the subject. The wheel may also be fixed with respect to the leg of the subject support lift in the locked position to resist movement of the lift in a lateral direction when moving the subject from one location to another.

It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus it is intended that the specification cover the modifications and variations of the various embodiments described herein provided such modification and variations come within the scope of the appended claims and their equivalents.